Methadone overdose killed Masterton mum

A 46-year-old Masterton mother died of a methadone overdose, according to a coroner's findings on the 2009 death.

Maureen (Becky) Rebecca Moenoa was found by her 13-year- old son on the morning of October 10, 2009.

The son had stayed at a friend's house the night before, texting his mum around 10pm, with no reply.

The next day he could not get into the house, so he left, returning around 10.30am to climb through a window, finding his mum on the couch with a blanket over her.

Toxicology reports showed Ms Moenoa had 2.6mg of methadone per litre of blood when she died, which is considered potentially fatal even for those who have a high tolerance.

According to the findings, Ms Moenoa had been a methadone patient with Wairarapa Addiction Services since 1995 and was on a daily dose of 150mg.

Richard McGrath said she had a history of associations with people who took drugs such as benzodiazepine and methamphetamine, and had tested positive for benzodiazepine in 2008. After seeing the initial toxicology report he prompted ESR to do further tests.

He said in his experience patients on methadone can often "double-up", taking a second dose of methadone in the same day without serious consequences, but if that was mixed with other illicit drugs the combination could be fatal.

ESR did not find any trace of illicit drugs in Ms Moenoa's blood. Wellington regional coroner Ian Smith concluded she had died of a methadone overdose.